M2 Tool Steel
|Tempering Temp. º(F):||Oil Quenched Hardness Rc||Air Quenched
Drills, taps, punches, reamers, broaches, planer knives, lathe tools, forge dies, form cutters, milling cutters, end mills, gear cutters.
Preheat to 1300° F - 1500° F and soak thoroughly. Then raise to 2050° F - 2100° F. Do not forge or roll below 1800° F, cool slowly from the forging or rolling temperature. Do not normalize.
Heat slowly to 1600° F, and hold for uniformity, cool at a rate of 30° F per hour to 900° F, then air cool. Expected Brinell hardness 241 max.
Preheat slowly to 1550° F, soak until uniformly heated, and heat rapidly to 2250° F - 2275° F. Heating times may vary from a few minutes to a maximum of 15 minutes, depending on the size of the tool. Oil quench to develop higher hardness, although air or hot salt quench may be used.
Temper immediately after quenching, before the part has cooled to below 150° F. A tempering range of 1000° F - 1050° F is recommended. Parts should be held a minimum of 2 hours per inch of thickness. Double tempering is recommended. The following tempering table may be used as a guide. 1" dia. specimens were used for this test, it may be found that heavier sections are several points lower. Table is based on a 2250° F hardening temperature.